Laser Intertial Fusion-Fission Energy [L.I.F.E.] (May 01, 2009)

Introduction:

With constant reminders of the tenuous state of energy production and the limited nature of the fuel resources that are commonly exploited for that purpose, it should be clear to almost all of us that drastic changes involving our energy sources and methods of production are required in order to sustain our worldwide culture and society into the future.  One of the alternatives that are now coming to light is the Laser Inertial Fusion-Fission Energy (L.I.F.E.) program that is now being developed at the National Ignition Facility found at the Lawrence Livermore National Laboratory in California. This research has the potential to greatly modify the landscape of both our social and scientific worldviews while providing a safe, clean, and efficient source of electricity fueled by a resource that is both abundant and not likely to become exhausted at any time in the foreseeable future. In the following pages I hope to provide a brief overview of the history and explanation of the processes involved, the program that is being developed at the National Ignition Facility, and the potential benefits that can be derived from the work that is being done.

Definitions and Relevant History:

The following paragraphs provide a basic working understanding of the process of nuclear fusion as well as a very brief overview of the relevant steps that have led to the development of the program housed at the National Ignition Facility.

In the 2008 report “Fusion as an Energy Source: Challenges and Opportunities” by W.J. Nuttall, fusion is defined as the formation of a stable atomic nucleus through the combination (fusing) of less stable, smaller atomic nuclei. The energy derived from a nuclear fusion reaction comes from the “difference between the nuclear binding energies of the initial and final components.” In the sun, fusion takes place at temperatures at around 15 million°C, whereas those in experimental reactors are closer to 100 million°C. A part of the reason for the greater temperature requirements for the fusion reactions that take place in laboratory environments here on earth as opposed to those that take place in stars is that the pressure and the mass of fuel involved is far greater in a star, and thus greater temperatures are required to produce similar reactions on Earth.

In the section, “How ICF Works” from the Lawrence Livermore National Laboratory website an overview of the attempts to develop internal confinement fusion since the 1940’s is detailed. In the earlier attempts magnetic fields are used in order “to confine hot, turbulent mixtures of ions and free electrons called plasmas so they can be heated to temperatures of 100 to 300 million kelvins.” With confined temperatures of that range heavy isotopes of hydrogen (deuterium and tritium) are capable of being fused into a heavy isotope of helium with a release of energy that is transformed from kinetic to heat as interactions with additional material takes place. Starting in the 1970’s, two types of inertial confinement fusion have been developed, the direct drive and indirect drive methods. The Indirect drive method is to be attempted first at National Ignition Facility, where “lasers heat the inner walls of a gold cavity called a hohlraum…” which will contain a tiny pellet of heavy hydrogen isotopes. This process is to result in the genesis of superhot plasma which radiates a uniform ‘bath’ of soft X-rays.”  These x-rays will cause the surface of the fuel pellet to heat up and ablate very rapidly while the pellet itself implodes, creating a hot spot in the center where the fusion is triggered. If everything goes according to plan, the energy production of the fusion process itself will exceed that required to power the laser and initiate the process by 10 to 100 times. Success with this objective will provide the first steps towards viable fusion-powered energy in commercial power plants.

The Program at the National Ignition Facility:

What follows is a description of both the lasers that have been developed for use in the L.I.F.E. program and the facility in which the experiments are to take place.

In the report provided by the U.S. Department of Energy in March of 2009 it was announced that the largest laser ever developed had been completed at the National Ignition Facility. This achievement is expected to increase national security, decrease American dependence on foreign oil, and usher in an opportunity to experience breakthroughs in numerous scientific fields. It is noted that this has not been the first groundbreaking achievement to be realized by those at the National Ignition Facility, as earlier in March of 2009 the National Ignition Facility was the world’s first laser to exceed a megajoule by producing more than 25 times the previous energy record with a recorded 1.1 million joules of ultraviolet energy.

“The National Ignition Facility: Ushering in a New Age for Science” found on the Lawrence Livermore National Laboratory website provides a detailed overview of what the facility actually consists of. When experimentation begins in 2010 they will take place in a facility that has dimensions of a ten-story building and three football fields. Inside of this massive structure are 192 lasers which are expected to produce at least 60 times the energy of any existing laser system. Once everything is in place, approximately two million joules of energy can be targeted on the central chamber which will simulate conditions otherwise only found in cores of stars, gas giant planets, and nuclear weapons. All of this carried out for the purpose of providing “significant contributions to national and global security,” and opening the door to the possibility of fusion energy as a practical source of energy.

Potential Benefits:

While there are likely to be multiple benefits that I did not touch upon in my research, the following paragraphs sum up what I felt to be the most important benefits that we stand to reap if the research being conducted is successful.

As it states in “Inertial Fusion Energy” on the Lawrence Livermore National Laboratory website, the program at the National Ignition Facility provides not only the opportunity to validate the viability of inertial fusion energy as a source for electricity, but just as importantly provides a potential energy source that  is not dependent upon rare or non-renewable resources. The fuel(s) required for the National Ignition Facility’s fusion program are “derived from water and the metal lithium, a relatively abundant resource.” Unlike the limited surplus of petroleum, coal, natural gas, and other non-renewable energy sources, heavy hydrogen constitutes “one in every 6,500 atoms on Earth…” This provides a fuel that is not only available worldwide but one that compares quite favorably with current fuel resources. “One gallon of seawater would provide the equivalent energy of 300 gallons of gasoline; fuel from 50 cups of water contains the energy equivalent of two tons of coal.”

According to the article written by Gail Overton for LaserFocusWorld, there are numerous potential benefits to be derived from the research being performed at the National Ignition Facility as well as at similar laboratories around the world. Reducing the quantity of carbon dioxide that is released into the atmosphere by replacing current fossil-fuel power plants with nuclear fusion power plants and dramatically reducing the amount of nuclear waste that is left behind by the presently utilized nuclear fission power plants being the two most important benefits from an ecological perspective. However, not only would nuclear fusion reduce the amount of nuclear waste compared to what is produced by nuclear fission, but once the process was underway, it could be used to, “consume the available stockpiles of spent nuclear fuel…” thereby actually reducing the amount of preexisting nuclear waste that is already a cause for concern.

Conclusion:

While there is no guarantee that the research being conducted at the National Ignition Facility will produce the results that are anticipated or that an industry developed around the process of inertial fusion energy production will arise with successful completion of the experiments that are underway, it is important that we explore new avenues and begin searching for new ways to both provide the necessary energy for our daily lives and diminish our negative impact on the world around us. There are numerous other alternatives being explored, and it may be that a combination of various energy sources is the best method available to us, but that requires that we explore these new potential sources of energy, and this paper was designed to sponsor an awareness of one particular method. If I have successfully provided a greater degree of understanding, both of the program located at the National Ignition Facility itself and of the benefits that we can hope to derive from that and related programs, then I have accomplished what I have set out to do.

Advertisements

UFOs and Alien Abduction (April 09, 2007)

I have never experienced anything in my life that could be considered paranormal. I have never witnessed anything that could be referred to as a UFO nor have I ever been abducted by aliens. Likewise I have never met anyone who claims to have witnessed a UFO or who claims to have been abducted by aliens. There are those who would claim that my inability to believe in such things is symptomatic of an insular frame of mind on my part. However I did not witness the “Big Bang”, I have never seen a subatomic particle with my own eyes, and I have never actually seen a distant star as anything other than the speck of light that it appears to be from Earth. I do believe in these things, because, though I cannot claim to have seen them with my own eyes, they make sense when placed into a framework with other things that I do know to be true. I believe in more than that which I have seen and experienced, but there is a degree of common sense and logic that needs to be applied to these things that remain unseen.

UFO sightings can be traced back to biblical times if some interpretations of Ezekiel 1: 4-28 are to be believed, even though biblical scholars have thoroughly addressed the misinterpretations applied to this story by individuals such as Erich von Daniken[i] in Chariots of the Gods?, a UFO fanatic’s bible. According to von Daniken, what Ezekiel witnessed was some manner of amphibious helicopter or another advanced form of technology not available to human beings at the time the story was written.

More recently, in fall of 2006, according to a report posted to the Associated Press[ii], a UFO was sighed in the sky above Chicago’s O’Hare airport, “The workers, some of them pilots, said the object didn’t have lights and hovered over an airport terminal before shooting up through the clouds.” FAA spokeswoman Elizabeth Isham Cory is quoted as responding, “That night was a perfect atmospheric condition in terms of low (cloud) ceiling and a lot of airport lights. When the lights shine up into the clouds, sometimes you can see funny things.”

Though there appear to be few credible arguments in favor of the existence of extraterrestrial visitations to Earth, there are many legitimate scientific explanations as to why so many people claim to have experienced alien abductions or witnessed what they insist was some manner of alien craft, the most well-understood being a phenomenon known as sleep paralysis. In her article “Abduction by Aliens or Sleep Paralysis?” a response to a Roper Poll that claimed an estimated 3.7 million Americans had been abducted, Susan Blackmore[iii] explains the phenomena known as sleep paralysis,

In a typical sleep-paralysis episode, a person wakes up paralyzed, senses a presence in the room, feels fear or even terror, and may hear buzzing and humming noises or see strange lights. A visible or invisible entity may even sit on their chest, shaking, strangling, or prodding them.

Blackmore further draws a correlation between the amounts of television an adult watched and their interpretation of how aliens would look based upon the results of a study she performed in Britain. 350 subjects, of varying ages and levels of education, were asked to relax and listen to a story about an alien abduction that Blackmore recited. Following this story Blackmore asked a series of questions and further requested that a number of the individuals taking part in this study draw a picture of the alien that they had envisioned. Though the results are necessarily ambiguous as far as confirmation or repudiation of actual abduction experiences, Blackmore does state, “These findings do not and cannot prove that no real abductions are occurring on this planet. What they do show is that knowledge of the appearance and behavior of abducting aliens depends…on how much television a person watches.”

Blackmore is not the only person to have reached the conclusion that most (if not all) experiences relating to alien encounters can be explained in terms of sleep paralysis. In an editorial piece for Scientific American, Michael Shermer[iv] states,

The most likely explanation for alien abductions is sleep paralysis and hypnopompic (on awakening) hallucinations. Temporary paralysis is often accompanied by visual and auditory hallucinations and sexual fantasies, all of which are interpreted within the context of pop culture’s fascination with UFOs and aliens.

This statement by Shermer is directly related to an alien encounter that he personally experienced while bicycling across the United States in August of 1983 during which,

A large craft with bright lights overtook me and forced me to the side of the road. Alien beings exited the craft and abducted me for 90 minutes, after which time I found myself back on the road with no memory of what transpired inside the ship. I can prove that this happened because I recounted it to a film crew shortly afterward.

Instead of operating under the assumption that he had actually been abducted, Shermer used his critical thinking skills and investigated the actual events surrounding his experience and concluded, “My abduction experience was triggered by sleep deprivation and physical exhaustion.”

Anyone familiar with the show The X-Files would probably be familiar with the poster of the “flying saucer” with the words, “I Want to Believe” emblazoned above. I can sympathize with the sentiment behind the statement. I also want to believe. I would be happy to believe that we have been visited by extraterrestrial intelligences. I would be content just to have some evidence, less profound than actual visitations, to support my belief that they are indeed out there somewhere. But I am unable to let my wistful desires influence my realistic analysis of the evidence at hand. This very desire to believe can serve as a severe handicap where our capacity to rationally assess situations is concerned. According to James Alcock[v], in the article “The Belief Engine”,

Beliefs can become very resistant to contrary information and experience. If you really believe that alien abductions occur, then any evidence against that belief can be rationalized away — in terms of conspiracy theories, other people’s ignorance, or whatever.

And conspiracy theories certainly abound when believers in UFO phenomena and alien abduction are questioned regarding the lack of substantiating evidence to support these claims. But Carl Sagan[vi] probably responded best to these conspiracy theories in an interview for NOVA when he stated, “because of human fallibility, extraordinary claims require extraordinary evidence.” I agree with Sagan’s stance completely. It is my opinion that the burden of proof lies on the shoulders of those who are attempting to make claims of an outlandish variety without any substantiating evidence.

There is very little doubt in the vast majority of those who constitute the relevant scientific fields (astronomy and the growing field of astrobiology to name only a couple) that extraterrestrial life does exist and that it has led to the development of intelligent life elsewhere. According to Dr. Frank Drake’s calculations there would be a minimum of approximately 10,000 worlds supporting intelligent life within just our own galaxy, primarily orbiting stars similar to our own and most likely found in what has come to be referred to as the galactic habitable zone. This hypothetical zone can be visualized in terms of a belt encircling the center of our galaxy meeting the conditions of being both close enough to the galactic center to benefit from a sufficiently high level of heavy elements and far enough distant that the greater propensity for asteroid and comet collisions as well as increased outbursts of radiation from supernovae can be avoided. It seems to be a viable assumption that there is other life out there, considering the sheer number of stars, even if only a small proportion of those actually harbor planets, a small number of which being rocky worlds similar to Earth.

Since 1960, thanks in large part to the efforts of Dr. Drake, there has been a growing program in place with the sole purpose of scanning the sky above us for any sign of intelligent life beyond our world. SETI (Search for Extraterrestrial Intelligence) has been growing not simply with a greater number of radio telescopes and subsequently a greater section of the sky being scanned at any given time, but these methods have been reinforced by implementation of equipment with greater and greater levels of sophistication, and yet according to Erik Skindrud[vii] in the article “The Big Question” he claims, “to this day no definite extraterrestrial signals have been recorded by the more than 70 radio searches undertaken.”

Many factors weigh heavily against extraterrestrial intelligence having visited our planet and these same factors work against our drive to explore and colonize beyond Earth. Distance, time, and cost-effectiveness stand in the way of our most imaginative plans of colonizing the moon or more distant Mars. Just the thought of expanding beyond the boundaries of our own solar system is almost alien when it comes to practical application. In order for an alien civilization from Proxima Centauri (the nearest star to our own) to have visited Earth this morning, they would have had to have left their own home world a minimum of 4 years ago traveling at the speed of light. Traveling any more slowly and that travel time increases exponentially. At our current level of technological advancement the resources required to undertake such a venture ourselves would bankrupt every civilized nation on Earth. An interesting question to me is, how utterly alien would another species have to be in order to overcome these limiting elements for themselves, and to what purpose?

Analysis Of the Fermi Paradox (April 01, 2007)

In the middle of the 20th century a physicist named Enrico Fermi posited the question, “Where are they?” in reference to extraterrestrial life. The age of the universe (calculated to be 13 billion years) and the great number of stars (estimated to be between 100 and 250 billion in the Milky Way alone) would imply that the universe should be teeming with life, and yet we haven’t received any confirmation of this. That apparent disconnect between what seems altogether likely, that there should be numerous technological civilizations laced throughout the universe, and that which is evident is the foundation of what has come to be known as The Fermi Paradox. Since that initial question was posed, physicists, biologists, and other scientists have been attempting to provide their own solutions to this conundrum. There are two primary schools of thought that have developed in response to this scenario. There are those who suspect that extraterrestrial life is out there, that we haven’t been looking hard or long enough, and that it’s only a matter of time before we find them (or they find us); and there are those who suspect that life is an exceedingly rare thing, and that we are unlikely ever to discover (or be discovered by) any life beyond the boundaries of this planet. There are only two ways to solve this debate, either we discover (or are discovered by) extraterrestrial intelligence or we spread throughout the whole of our own galaxy and use a process of elimination to rule out that there is or has been life around another star. So far we are doing our best to work towards that first potential solution, but we still have a long way to go.

Many problems arise when it comes to the search for extraterrestrial intelligence, not the least of which being scale and time. According to recent research performed by physicist Rasmus Bjork of the Niels Bohr Institute, current calculations indicate that it would take approximately 10 billion years for a civilization to explore less than 1% of the galaxy, traveling at a tenth of the speed of light., so even if we could receive signals from another intelligent civilization the likelihood is small that we could ever reach them. Regardless of this daunting realization we do have multiple programs in place which are engineered specifically for the purpose of scanning the galaxy for any trace of life that might be there to be discovered.

The first of these programs is known as SETI (Search for Extraterrestrial Intelligence), established in 1960 by Frank D. Drake, who believed that water bearing planets were common in our galaxy. Presently SETI consists of a series of radio telescopes tuning into the frequencies emanating from space, in search of any kind of discernable signal that could be intelligent in origin. In an article by Erik Skindrud it is stated,

Recent discoveries have confirmed many of Drake’s assumptions. Within the past year, astronomers discovered several planets that orbit other stars. Scientists have found complex organic molecules floating in interstellar space. And NASA stunned the world with evidence that primitive life may have existed on Mars several billion years ago. (Skindrud 152)

Where signals from other intelligent life is concerned, we have yet to meet with any success, but that lack of success doesn’t dissuade individuals like Dr. Geoffrey Landis of the Ohio Aerospace Institute, “One likely reason we have not yet detected extraterrestrial civilizations by radio is that SETI searches are likely simply listening at the wrong range of frequencies” (Landis 163). Landis further speculates “It is also possible that a civilization interested in communicating across interstellar distances would not use high beamspread techniques like radio at all, but would use much shorter wavelength and hence more directed means” (Landis 163). It seems that he hasn’t been able to determine any solution to this primary problem standing in the way of SETI being ultimately effective beyond methods that would be extreme in nature,

Unless the antenna size is unrealistically large (thousands of kilometers), across interstellar distances the overwhelming majority of any signal sent by radio will be broadcast to the empty space between the stars. (Landis 163)

Cost effectiveness comes into play heavily when it comes to the methods we are capable of employing in our search.

Another of the programs that we have in place is the Terrestrial PlanetFinder, and the earlier (and admittedly, less advanced) incarnations of this same search for planetary bodies orbiting other stars. According to Alan Longstaff with the Royal Observatory Greenwich in London, “Over 120 extrasolar planets have been found orbiting 105 stars” (Longstaff 28). But finding planets is only a portion of the problem, the vast majority of the planets we are discovering are of the gas giant classification, and those are not (to the best of our current knowledge) capable of supporting intelligent life. But there is hope, according to Longstaff, “If a growing planetary system retains enough dust for the much slower building of terrestrial planets, then about half the known extrasolar systems could form Earth-mass planets in their habitable zones” (Longstaff 28).  The key, Longstaff urges, is that we look for subtle signs of life when we do finally begin examining rocky planets, that what we’re looking for are

tantalizing spectral lines of biomolecules in the light from a distant earthlike world, or structures within rocks from another planet that are not of obvious geological (or even biological) origin. When we discover any such evidence — actually, long before we reach that point — we’re going to need a working definition of what life is and how we’ll recognize it. (Longstaff 28)

Longstaff brings up an interesting point in that statement regarding our capacity to recognize life for what it is when we may have an unintentional bias towards the specific types of life that we are familiar with here on Earth. This issue is definitely one that we will need to address in great detail when it comes time to analyze potential life-bearing planets, and is one that the burgeoning field of astrobiology is taking steps to categorize.

Now that the two major programs relating to the search for extraterrestrial life have been introduced it is time to discuss where we should be looking. The subject of habitability is a major issue in our speculations regarding alien life. Assuming that we are looking for life similar to our own, we do have a rough approximation of the conditions required to produce and support that life. According to Margaret Turnbull,

Part of the search for living worlds beyond the solar system involves the idea of a habitable zone around each star. This is a region where the temperature is right for the presence of liquid water on an earthlike planet. (Turnbull 58)

This particular region of orbit around the parent star is reasonably well understood, the problem with habitability is not so much one of distance but one of time.

The first requirement — habitability over billions of years — puts strict constraints on several stellar parameters that are easily observed. Young stars are not the best places to look. Not only has life had less time to develop, but, for the first billion years or so, asteroids and comets bombard the system, frustrating life’s efforts to survive. It turns out that stars — like adolescents entering adulthood — go through a significant decrease in flaring and other chromospheric activity after an age of 3 billion years. The Sun is one such example of a star that significantly decreased its flaring activity at an age of 3 billion years. Whether this newfound calm helps life form is unclear, but, at the very least, this lets us identify and rule out the youngest stars from our searches. (Turnbull 58)

The issue of habitability isn’t isolated to the scale of a solar system however, as it has been speculated that there is a specific area of our galaxy that could be categorized as the galactic habitability belt, where the stellar bodies are far enough apart from one another that there isn’t a constant bombardment of radiation that would be deadly to life as we know it.

Ultimately I am a believer. I happen to feel that there is life out there beyond the bounds of both our planet and our imaginations and I feel that it is simply a matter of time before we find what we are looking for. Whether this discovery will happen within my lifetime is relatively unimportant in contrast to the sheer importance of the discovery itself. I do sometimes find myself wondering the same thing that Fermi did back in 1950, but I’m patient enough to accept that it will take time before I know the answer to that important question, “Where are they?”